Method for transmitting data in a network of distributed stations, and network station

ABSTRACT

The invention relates to the technical field of home networks. A home network based on the present UPnP standard (Universal Plug and Play) allows data to be interchanged between network subscriber stations. A UPnP standard may have one or more control point devices. To allow profile information such as user profile or network profile to be interchanged, the invention proposes providing a control point device firstly with an expanded device ascertainment service which can be used to find the other control point devices in the network and also with one or more additionally implemented profile services which allow the other control point devices in the network to be notified about change to profile information on a control point device.

This application claims the benefit, under 35 U.S.C. §365 ofInternational Application PCT/EP2006/060138, filed Feb. 21, 2006, whichwas published in accordance with PCT Article 21(2) on Sep. 14, 2006 inEnglish and which claims the benefit of German patent application No.102005011333.8, filed Mar. 11, 2005.

The invention relates to the technical field of home networks.

BACKGROUND OF THE INVENTION

A wealth of different standards have been elaborated, in part withdifferent aims, for networking devices in the household. One of thesystems provides for the devices to be networked on the basis of the“Internet protocol” IP. The system has become known by the abbreviationUPnP, which stands for Universal Plug and Play. A UPnP standard iscurrently available in version 1.1. More detailed information regardingthe UPnP system and the associated standard can be found on the officialInternet page of the UPnP consortium.

The UPnP system has no restrictions regarding the device types. This isintended to allow both devices from the consumer electronics field, suchas TV, DVD player, set-top box, video recorder, camcorder etc., and alsoother devices in the household, for example washing machine, chillers,heating control, coffee machines, lighting and shutter control, alarmsystems and others, to be networked. Personal computers may likewise beregarded as belonging to the category of consumer electronics devices.These are also covered by the UPnP system and can also be integratedinto the network.

However, the UPnP system does not contain a specification for the lowerlayers of the OSI/ISO reference model for data communication. Thisconcerns particularly the physical layer and the data link layer. TheUPnP system therefore no longer contains a specification regarding whattransmission medium needs to be used to transmit the data which are tobe interchanged. Different transmission standards are permissible inthis case. Examples of suitable transmission standards are the Ethernetprotocol, the IEEE-1394 protocol, and even wireless transmission basedon IEEE 802.11x, Bluetooth or Hiperlan/2 are likewise suitable.

The UPnP specification describes how devices based on the UPnP standardare designed and how they can be controlled. One of the basic ideas ofthis specification is that it is possible to operate any UPnP deviceusing a standard HTML browser. To this end, every UPnP device has a webserver on which it is possible to store the HTML pages for operating thedevice (the “presentation pages”).

In the UPnP standard, the localization of UPnP devices in the network isthe responsibility of “control point devices”. However, this involvesthe respective UPnP devices themselves registering with the controlpoint devices. Equally, control point devices can look for UPnP devicesin the network.

When a control point device has found a UPnP device, it fetches thedevice's description from the URL (Uniform Resource Locator) indicatedduring registration using the HTTP and TCP-IP protocols. The UPnP deviceprovides the description in the form of an XML document. Using theinformation which the control point has obtained from the device'sdescription document, this device can now send “SOAP messages” (SimpleObject Access Protocol) to the device's control URL in order to controlsaid device.

INVENTION

Often, a UPnP network will contain not just one control point device butrather a plurality thereof. The user interface for controlling a devicefrequently provides an opportunity to create a network profile or userprofile. Such profile information may relate to the preferred musicalorientation in the case of an audio device, for example, or to thepreferred categories of TV programmes or the favourite TV channels inthe case of a TV set. Other examples of such profile information are alist of frequently used Internet pages or particular setting states fordevices in the household for different times, such as a day, night orholiday program.

It is an aim of the invention to allow profile information to beinterchanged between the various control point devices in the network.To this end, the control point devices first need to be provided withthe capability of localizing other control point devices in the network.Although the UPnP standard provides the control point devices with adevice identification service, they cannot use this service to find anyother control point devices in the network. This is because the UPnPstandard has no provision for this. The invention therefore first of allproposes providing an expanded device identification service on thecontrol point devices in the network. There is also provision for acontrol point device to contain an additionally implemented profileservice which the control point devices use to provide profileinformation. This also allows profile information to be interchanged.

The measures presented in the dependent claims permit advantageousdevelopments and improvements. Advantageously, the control point devicescan be notified about changed profile information using the eventmessages provided in the UPnP standard (Event Notification). To thisend, the control point devices register with the other control pointdevices in the network for notification in the event of the profileinformation being altered. If the profile information is stored as avariable, the event message is used to notify the other control pointdevices about any alteration to this variable.

The profile information may advantageously relate to a user profile.Equally, the profile information may also relate to a network profile.The user profiles or network profiles may differ according to time ofday, day of the week, month or season, or a special time such as aholiday or business trip. When a control point device has been notifiedof changed profile information, this control point device can transferthe new profile information to its own profile. In this regard, it isadvantageous if the profile information is linked to currency-levelinformation, in order to be able to check how current the profileinformation which has been communicated is. The profile informationcommunicated would advantageously be transferred only if it is found tobe more current than the information which is still stored in thecontrol point device's own profile.

Conversely, the profile information may be linked to transfer controlinformation, possibly in addition to the currency-level information.This condition information is intended to indicate in the changenotification that the new information is to be transferred from theother control point devices in the network, possibly regardless of thecurrency-level information. The transfer control information is thenadvantageously information which the user himself has input, which meansthat he retains full control over the profiles which are to be changed.

Corresponding advantageous measures for a network station as controlpoint device in the network are presented in Claims 11 to 19.

DRAWINGS

Exemplary embodiments of the invention are shown in the drawings and areexplained in more detail in the description below. In the drawings:

FIG. 1 shows a basic diagram of the transmission of AV data between twonetwork stations in line with version 0.83 of the UPnP-AV architecture;

FIG. 2 shows an example network with UPnP-AV devices;

FIG. 3 shows a first example of a control point device based on theinvention;

FIG. 4 shows a first example of a profile service;

FIG. 5 shows an example of a status variable for the profile serviceshown in FIG. 4;

FIG. 6 shows a second example of a control point device based on theinvention;

FIG. 7 shows further examples of profile services based on theinvention; and

FIG. 8 shows an example of an XML device description for a control pointdevice based on the invention.

EXEMPLARY EMBODIMENTS OF THE INVENTION

As part of the UPnP standardization, a specification for transmitting AVdata (audio/video data) between network subscriber stations has alsobeen drawn up, and concluded in June 2002. The exact title of thisspecification is: UPnP-AV architecture: 0.83 dated 12 Jun. 2002. Thisspecification defines three different types of devices for transmittingAV data. First, a “MediaServer”; this denotes that device which isselected as the source of the AV data. Secondly, there is the devicetype MediaRenderer, which is a device which is used as a data sink forthe AV data. Thirdly, as a separate device type, the Control Point typeis also provided, which is called a control point device below. As anexample, a universal remote control for the AV devices is regularlyconsidered to be a control point device. Alternatively, however, apersonal computer in the network can also perform this task or else a TVset with a remote control may likewise be suitable as a control device.

The control point device communicates with two other UPnP devices whichare suitable as a data source and a data sink for a desired AVconnection. The control point device initializes and configures bothdevices for the AV connection, so that the desired data stream can alsobe set up. Hence, the task of a control point device is typically to setup an AV connection between two network subscribers, possibly to makechanges to the settings of the two devices, and, when the desired AVdata stream has been transmitted, to cut the connection again, i.e. toask both devices on the AV connection to delete the data whichcharacterize the connection. However, control point devices in the UPnPstandard are not specified to the extent that a complete API(Application Interface Program) is known for this device type.

FIG. 1 shows the basic classification of network stations which areneeded for an AV connection. The MediaServer device contains or hasaccess to an AV data stream which, by way of example, is stored locallyor is received externally. The MediaServer device has access to the AVdata and is able to transmit an associated AV data stream to anothernetwork station via the network. In this case, the AV data stream istransmitted using a transfer protocol in line with the transmissionmedium which is provided in the network. The data transmission formatssupported by the MediaServer are defined explicitly for every possibleresource in the content directory service. Typically, the MediaServerdevice type can be assigned to one of the following devices: digitalvideo recorder, CD/DVD player, camera, camcorder, PC, set-top box,satellite receiver, cassette recorder etc. To select a particular AVcontent, a module for a content directory is usually implemented in theMediaServer in accordance with the UPnP standard. Besides this, there isalso a module which is called a Connection Manager and which the controlpoint device uses to communicate with a MediaRenderer when a connectionis set up.

A MediaRenderer device receives the AV data stream sent by theMediaServer and outputs it either as image information or as audibleinformation. Similarly, the MediaRenderer device likewise contains animplementation of the Connection Manager module for communication withthe control point device when a connection is set up. In addition, aRendering Control module is implemented in the MediaRenderer device.This module receives commands for setting reproduction characteristics,such as volume, tone, definition, contrast, brightness, colour etc., andimplements them.

Cited examples of devices which should be assigned the device typeMediaRenderer in the home network are a TV set, a stereo amplifier andan MP3 player. Depending on the transmission format implemented, theMediaServer or the MediaRenderer also has an AV transport service whichis used to control the data transfer and the reproduction (e.g. play,stop, fast forward etc.).

A control point device coordinates the data transport betweenMediaServer and MediaRenderer. It is likewise used to implement theoperating commands from the operator and to forward them to theappropriate devices on the AV connection. In this case, the commandsplay, stop, pause, fast forward, rewind are particularly suitableexamples. As mentioned at the outset, control point devices are alsodesigned to find and control standard UPnP devices.

As FIG. 1 shows, the transmission of the AV data in line with theimplemented AV transport protocol is independent of the communicationwith the control point device. The data stream is therefore transmittedeven when the control point device has logged off from the network afterthe AV connection has been set up. Since the known transport protocolsare standardized, no further information is provided in this regardbelow.

FIG. 2 shows a simple home network. All the devices in this networkwhich are designed on the basis of the UPnP-AV specification are shown.The reference numeral 10 denotes a DSL modem. This is usedsimultaneously as the DSL router and as a network switch. The DSL modem10 has the individual network stations connected to it in star form. Thenetwork connection technology used is Ethernet network technology. Thereference numeral 17 denotes the telephone line to which the DSL modemis connected and which can be used to access the Internet. The DSL modem10 may be configured as a UPnP Internet gateway device within thecontext of the UPnP specification. The reference numeral 11 denotes aflat screen device, such as an LCD television set or a plasma televisionset. This device has two UPnP device types. First, the flat screendevice 11 can be regarded as a MediaRenderer device and is likewiseconfigured as such too. In this case, it is used to show video contents,and possibly audio contents if the device is equipped with its ownloudspeakers. Secondly, the device is also used as a control pointdevice for controlling the other network stations.

The reference numeral 12 denotes a personal computer. This also has thefunctionality of a control point device. This is the typical task of thecomputer in the network. Secondly, the personal computer can also adoptthe functionality of a MediaServer and also that of a MediaRenderer.

The reference numeral 13 denotes a digital satellite receiver. Thisdevice is of the MediaServer type. The reference numeral 14 denotes adigital video recorder. This device is also configured as a MediaServerdevice. This is equally true of the DVD player 15 which is also presentin the network.

In addition, an AV receiver 16 is also shown. This device is usedfirstly for radio reception, and secondly also for amplifying audiosignals and for outputting the audio signals on connected loudspeakers.This device thus internalizes both functionalities, MediaServer andMediaRenderer.

In the example shown in FIG. 2, not all of the devices shown need to beset up in one room. They may also be distributed over a plurality ofrooms. By way of example, in practice it can be assumed that the flatscreen device 11 and the personal computer 12 are accommodated indifferent rooms. It is thus possible to access the network fromdifferent rooms. The output of audio contents is not limited to the roomin which the AV receiver 16 is positioned. First, the connectedloudspeakers may be accommodated in different rooms, and secondly it isalso possible to output audio contents in the room in which the personalcomputer 12 is set up, for example.

In addition, it is assumed in the exemplary case shown in FIG. 2 thatboth the personal computer 12 and the flat screen device 11 are equippedwith an Internet browser. For a flat screen device, there is often a“digital signal processing box” in which the relevant module for theInternet browser may be arranged. The flat screen device 11 is operatedusing a typical remote control or conveniently using a radio keypad, forexample. In the case of an Internet browser, it is normally possible tostore frequently visited Internet pages as a favourites list or as abookmark. If an entry is now added to the favourites list on oneInternet browser, it may be desirable to transfer it automatically tothe Internet browser of the other device in the network too.

It is similarly possible to access audio or video contents, storedeither in the digital video recorder 14 or in the personal computer 12,both using the flat screen device 11 and using the personal computer 12.This also allows the user to create favourites lists or to store profileinformation, as in the case of particularly desired musical orientationsor genre orientations in the case of video contents. Examples ofcategories of audio documents are classical, jazz, rock, pop, rock androll, folk, country, techno etc. Examples of categories of videodocuments are action, comedy, adventure, science fiction, western,fantasy, thriller etc. The situation is similar for television too.Nowadays, the user can often store his viewing habits likewise in aprofile, which means that he can create favourites lists, for example,with particular TV channels or can have recommendation lists created forparticular categories of television programmes, such as news, reports,feature films, sport, culture etc.

An example of the way in which a recommendation list for playback ofaudio contents can be constructed is found in the earlier patentapplication EP 04 291 150.3.

The text below gives a more detailed explanation of how it can be madepossible for this profile information which is present in the network tobe interchanged between the control point devices 11 and 12 in theexample network in FIG. 2. To this end, FIG. 3 shows the necessarycomponents in the control point device. The design shown is valid forboth control point devices 11 and 12 in the network. The referencenumeral 20 denotes a web server. On this, the device provides adescription of the device in the form of an XML document. Thisdescription contains information about the manufacturer, the serialnumber, the URLs for control, events and the presentation. For eachservice which the device provides, commands and actions and also filetypes and a data range or variable types and a value range arespecified. An example of such an XML device description is shown in FIG.4. The device type indicated in row 8 is highlighted, said device typebeing set as ControlPoint and thus indicating that it is a control pointdevice. In the list of available services which is presented furtherbelow, the service for synchronizing the web browser is shown as anexample. The other services for synchronizing the music browser and thefavourites list of TV channels are merely indicated, but are alsocontained in the list.

The reference numeral 21 denotes a device identification service.According to the UPnP standard, this component is absolutely essentialfor a control point device. This service allows control points to lookfor UPnP devices in the network. This is the responsibility of the SSDPprotocol (Simple Service Discovery Protocol). However, the UPnP standardcontains no provision for the control point devices in the network alsoto register automatically with the other control point devices in thenetwork when connecting to the network. Even in the event of a searchrequest from the control point device to all the network stations whichis provided in the SSDP protocol and is sent using a “multicast address”and port number 239.255.255.250:1900, the control point devices whichare present in the network would not subsequently register.

In line with the invention, the device identification service 21 isexpanded. In this case, a special device type and service type arestipulated for a control point device, which means that the controlpoint devices likewise send an ssdp:alive message when connecting to thenetwork, with its associated entry for the notification target NT. Thereis likewise support for a control point device to be able to searchspecifically for control point devices in the network. The appropriatesearch target is thus entered under the entry ST in the search requestM-Search. The control point devices being sought would then registerusing the appropriate response message within the context of thediscovery protocol. For further details in this regard, reference ismade to the UPnP specification. This expanded device identificationservice 21 provides the individual control point devices with knowledgeof one another and allows them to communicate with one another.

The reference numeral 22 denotes a profile service from the controlpoint device. This supports the interchange of profile information. Forevery defined profile in the control point device, the profile service22 contains at least one variable. Thus, by way of example, thepreferred musical orientation can be characterized by a variable, whichis then linked to a set of entries, for example jazz, pop, folk. For afavourites list for TV channels, a variable may likewise be madeavailable which is then likewise again linked to a set of TV channeldescriptors, for example ARD, ZDF, N3, RTL, SAT1, PRO7, WDR, Kabell,Eurosport, DSF. A similar situation applies to the profile for thefrequently called Internet pages. In this case too, a separate variablemay be provided. The profile service is described in the associated XMLdocument of the control point device, as mentioned previously. There isthus the possibility for the other control point devices in the networkto register for the alteration in the variables of the profile service22. This is done as prescribed in the UPnP standard, using the XML-basedGeneral Event Notification Architecture (GENA). In the UPnP standard,the procedure which can be used to register for state changes in avariable is called Eventing:Subscription.

Every time an alteration occurs in one of the registered variables, thecontrol point device on which the alteration has occurred sends amessage to inform the other control point devices which have registeredabout the altered state. This is done using an event message, which iscalled an Eventing:Event Messages:Notify message in the UPnP standard.In the case of the invention, only an alteration which has been broughtabout by the user is communicated, that is to say when the alterationhas been made by the application program which sets up the userinterface.

As application programs, FIG. 3 also shows the application programs foran Internet browser 23, a music browser 24 and a user interface for atelevision set 25. Within these applications, there are also separatelyhighlighted areas in which the profile information, that is to sayfavourites list for Internet pages 26, preferred musical orientations 27and preferred TV channels 28, are stored.

An example of a profile service is shown in FIG. 5. This is an XMLdescription for this service. There, the status variables listed are thevariables Bookmarks, FavouriteMusicStyle and FavouriteTVChannels. Theseserve to synchronize the profile information for the three applications23 to 25. The respective beginning also contains a definition that thestatus variable is incorporated in the eventing method of UPnP, that isto say the communication of the changed variables to all thesubscribers.

A second example of a control point device based on the invention isshown in FIG. 6. In contrast to the example shown in FIG. 3, separateprofile services 22, 29, 30 for each of the three applications areformed in this case.

The XML descriptions for the two separate services SyncWebBrowser andSyncMusicBrowser are shown in FIG. 7.

An example of an XML description of a status variable based on theinvention is shown in FIG. 8. This figure shows the status variablecalled Bookmarks for the SyncWebBrowser service. Provision is made forthe beginning to have time information providing information about therespective currency-level status of the variable. This should preferablyshow the time and the date from a real-time clock. The two sync optionsTimeStampSync and ForceSync can be used to stipulate whether or not thecommunicated, altered variable is to be transferred only using the timeinformation.

TimeStampSync=No

ForceSync=No

means that transfer of the communicated change is not permitted.

TimeStampSync=Yes

ForceSync=No

means that transfer of the communicated change is permitted if the timeinformation is found to be more current.

TimeStampSync=No

ForceSync=Yes

means that transfer of the communicated change is absolutely necessarywithout considering the time information.

TimeStampSync=Yes

ForceSync=Yes

is not defined and is available for future expansions.

In addition: this allows the control point devices, which themselveshave also stored appropriate profile information, to compare whethertheir current profile information is outdated in comparison with thenewly communicated profile information. If so, the latter is transferredto their own profile. If not, the communicated information can also beblocked out. If a control point device contains no real-time clock ofits own, it may be appropriate to omit the currency-level information.

As a further possibility, it would be desirable to allow the user tostipulate whether or not an alteration in the profile should actually betransferred to the other profiles. This transfer control information ofthe type Syncoption 1 and 2 would then also be transmitted to thecontrol point devices when anything has changed in the profile and thecontrol point devices which have received the new profile are thendesigned such that they evaluate the transfer control information andtransfer the new information only if the transfer control signal hasbeen set. This means that the user retains full control over his createdprofiles.

In the lower part of the XML description of the status variableBookmarks in FIG. 8, the various entries for the marked Internet pagesare listed.

The invention is not limited to the exemplary embodiments mentioned. Itcan also be used for “network profiles”. These are profiles which areused to produce a particular state in the network or to monitor statesin the network. By way of example, profiles for various times of day,day, night, for various days of the week, for various months, forvarious seasons or for various special times such as a holiday orbusiness trip are suitable. In this case, it is then possible to enterdifferent states for particular control devices in the network. Examplesof these are a shutter control, heating control, alarm system setting,warning control, video recorder setting etc.

1. Method for transmitting data in a home network of distributedstations, in which said distributed stations the functionalities of adevice to be controlled are provided on a web server in the form of oneor more information pages generated using a description language and areselected by a control point device in order to control a device at thehome network which is to be controlled by means of a browser, wherein anexpanded device ascertainment service in the control point device isused to find other control point devices in the home network in order totransmit user profile information between two or more control pointdevices in the network, with one or more additionally implemented userprofile services in the control point device being used to send anotification about changed user profile information to the other controlpoint devices in the home network, wherein a list of device types isextended with a device type control point device, and the expandeddevice ascertainment service is making use of a discovery protocol inwhich the two or more control point devices are searchable based on anassigned device type or service type, wherein for searching a controlpoint device the expanded device ascertainment service in a requestingcontrol point device is entering a device type control point as a searchtarget in a search request and the expanded device ascertainment servicein the search target control point device is answering to this searchrequest in a response message.
 2. Method according to claim 1, whereinthe user profile service sends the notification about changed userprofile information to all those control point devices which have beenregistered for notification about changed profile information.
 3. Methodaccording to claim 1, where the user profile information comprises auser profile about a preferably desired musical orientation, apreferably desired TV or radio channels or programmes, or a list ofselected Internet pages.
 4. Method according to claim 3, wherein theuser profile differs according to time of day, day of the week, month orseason, or a special time such as a holiday or business trip.
 5. Methodaccording to claim 2, wherein the control point device which has beennotified about changed user profile information transfers the changeduser profile information to its own user profile.
 6. Method according toclaim 1, wherein the user profile information is linked tocurrency-level information.
 7. Method according to claim 6, wherein thechanged user profile information is transferred to the control pointdevice's own user profile only if the currency-level information showsit to be more current than the information in the control point device'sown user profile.
 8. Method according to claim 6, wherein the userprofile information is linked to transfer control information, whichindicates whether the changed user profile information is to betransferred from the other control point devices in the home networkregardless of any currency-level information which is present.
 9. Methodaccording to claim 1, wherein the home network of distributed stationsis a network based on the UPnP standard, corresponding to Universal Plugand Play.
 10. Home network station as control point device for acting asa requesting control point device in the method according to claim 1,with one or more user profile information items, wherein, the homenetwork station has an expanded device ascertainment service which canbe used to find the other control point devices in the home network, andin that one or more additionally implemented user profile services areprovided which are used to notify the other control point devices in thehome network about changed user profile information, wherein a devicetype control point is assigned to the control point device and theexpanded device ascertainment service is adapted to make use of adiscovery protocol in which control point devices are searchable basedon the assigned device type control point, wherein for searching acontrol point device the expanded device ascertainment service isentering the device type control point as a search target in a searchrequest sent to said distributed stations in the network.
 11. Homenetwork station according to claim 10, wherein the home network stationcomprises registration means which can be accessed by the other controlpoint devices in the home network in order to register for notifyingabout changed user profile information.
 12. Home network stationaccording to claim 10, wherein the user profile information relates to auser profile about preferably desired musical orientation, preferablydesired TV or radio channels or programmes or a list of selectedInternet pages.
 13. Home network station according to claim 11, whereinthe user profile differs according to time of day, day of the week,month or season, or a special time such as a holiday or business trip.14. Home network station according to claim 10, wherein the controlpoint device which has been notified about user profile informationtransfers the changed user profile information to its own user profile.15. Home network station according to claim 10, wherein the user profileinformation is linked to currency-level information.
 16. Home networkstation according to claim 15, wherein the changed user profileinformation is transferred only if it has been found to be more currentthan the information in the user profile.
 17. Home network stationaccording to claim 10, wherein the user profile information is linked totransfer control information, which indicates whether the changedinformation is to be transferred from the other control point devices inthe home network regardless of any currency-level information which ispresent.
 18. Home network station according to claim 10, wherein thehome network station is designed on the basis of the UPnP standard,corresponding to Universal Plug and Play.
 19. Home network station ascontrol point device for acting as an answering control point device inthe method according to claim 1, with one or more user profileinformation items, wherein, the home network station has an expandeddevice ascertainment service which can be used to find the other controlpoint devices in the home network, and in that one or more additionallyimplemented user profile services are provided which are used to notifythe other control point devices in the home network about changed userprofile information, wherein a device type control point is assigned tothe control point device and the expanded device ascertainment serviceis adapted to make use of a discovery protocol in which control pointdevices are searchable based on the assigned device type control point,wherein for searching a control point device the expanded deviceascertainment service is answering to a search request in which thedevice type control point is entered as the search target in a searchrequest in a response message.